Laminated wood wheel and method of making same



Feb. 5 1946. D. M. POPE ETAL.

, LAMINATED WOOD WHEEL AND METHOD OF MAKING SAME Filed Oct. 12, 1942dies and the entire wheel pressed together under a hydraulic pressure of500 pounds to the square inch and at a temperature of 300 F. These dieshave recessed or concave faces and produce the completed assembly shownin Fig. 2, exceptthat the assembly at this'stage lacks therivets 36.

The wheel is then bored through a spot mark placed on the side plates atthe time they were molded, the bit passing through the two side platesand center core to form the axle beari'ng 32, clearly shown in Figs. 1and 2 of the draw- It is to beunderstood that the particular wheel I bepainted, lacquered, varnished'or finished in any other suitable mannerimmediately after the entire assembly has been removed from the finalhot pressing operation. Where rivets are added tonthe. wheel, suchfinishing operation would orplaced in the wheel.

dinarily beperformedafter the "rivets had been selected for purposes ofillustration is merely one of many possible embodiments of our inventionand that the particular pressures, temperatures,

ing. The wheel is then placed on a centering pin 7 and turned slowlyagainst high 'speedcutting knive which give the final finish to thewheel and make it perfectly round in relation to its axle thicknesses ofwood, number of laminations, number of segments and type of bondingmaterial usedmay be varied without departing from the scope of ourinvention. The kinds of woods spe The wheel resulting from the foregoingsteps is V 7 complete and entirely satisfactory for most uses. The urearesin forms a permanent waterproof bond which is stronger than the wooditself. .This bond is slightly resilient and will not shatter under ablow and this resiliency permits the bond to give with the, wood andretain a firm grip on the wood under all stresses and strains to whichthe wheel is subjected.

Our novel wheel has several advantages to which we wish to callparticular attention; The rim is homogeneous and continuou and is notweakened by the pressure of spoke sockets or other interruptions to itscontinuity. The grain of'the wood is arranged substantially radially ofthe rim and when this rim is subjected to. con-' siderable wear orstrikes objects which would ordinarily splinter wood in its naturalstate, the end grains of the fibre tend to'mushroom out and to remainattached to the rim. The more the rim is abused, the softer the outerpart of the rim becomes without in any appreciable way losing itsroundness or ability to withstand indefinitely further shocks and wear.

The side plates form strong and continuous but light supports connectingthe rim with the axle core. The curvature of these side plates permitsthe use of arelatively long axle core with a mar-.

row rim and provides a wide axle bearing without appreciable increase inweight. This curvature also increases the lateral strength of the sideplates and of the entire wheel. tween the rim and the'core reducesweight and eliminates wood where additional strength is not needed. Ournovel design fully'develops the tensile strength of the Wood and leavesthe wheel,

separate operation, as desired. Washers 38 "are preferably interposedbetween the enlarged ends of the rivets and the side plates to preventthe ends of the rivets from cutting into the side:

plates. While the wheel would stand up without these rivets inordinaryusage, the rivets give a double guarantee against: any possiblesplitting of th'ewood and once these rivets arein placethe entireassembly is tied together, irrespective .of any individual failure ofthe resin bond or split: ting of any individual piece of wood.

Where the wheclis used withoutrivets, it may The space be- 5 core,subjecting the assembly thus formed to stituting merely typical examplesof various k nds of wood suitable for our purpose and the urearesin'referred to is merely a typical example of'a bonding materialbelonging to a group of thermo-setting plastics. Our invention is to beconstrued as including all variations and modificationsfalling withinthe scope of the appended claims. r

We claim:

1. That method of constructing a laminated Wood wheel which comprisescutting out a plurality of equal arcuate wooden segments, arranging saidsegments to form a plurality of rings, securing together the segmentsforming 'each ring, superimposing the several rings with urea resintherebetween'and with the joints ber 7 tween the segmentsof each ringoffset from the joints between the segments of all the other rings,subjecting the stack of rings thus formed topressure and heat to moldsaid rings into a permanent rim, cutting out a plurality of circular,fiat blanks ,of wood, placing a plurality} of said blanks upon eachother with urea'resin therebetween, subjecting said blanks to pressureand heat'andsimu'ltaneously ofisetting the central portion of saidblanks to form a permanent molded side plate, forming an axle core ofwood, assembling said core and mm in spaced relation between a pair ofsaid side plates and with urea resin between said side plates and thecontacting surfaces of said rim and core, subjecting 2. That method ofconstructing a laminated wood wheel which cor'np'rises cutting out aplus rality of equal arcuate wooden segments; ar

ranging said segments to form aplurality of rings,

securing together the segments forming each ring,

superimposing the several. rings with thermosettir'ig'resin therebetweenand with the joints between the segments :of each ring ofiset from thejoints between the segments of all the other .rings, subjectingthe.stack of rings thus formed to pressure and 'heat to mold saidrings intoa permanent rim, cutting out a plurality of circula'r, fiatblanksoff-wood, placing a plurality of saidblanks "upon each other withthermo-setting. resin therebetween, subjecting said blanks to pressureand heat and'simultaneously oiiset ting the central portion'of saidblanksto form a permanent molded side'plate, forming anaxle core ofwood, assembling said core and rim. in spaced relation between a pair ofsaid side plates and with thermo-setting resin betweensaid side platesand the contacting Surfaces of said rim and heat and pressure to setsaid thermo-setting resin andthereby form a permanently bonded wheel,and forming a bearing in said side plates and core.

3. That'method of constructing a laminated wood wheel which comprisescutting out a plurality of equal arcuate wooden segments, arranging saidsegments to form a plurality of rings securing together the segmentsforming each ring, superimposing the several rings with urea resintherebetween and with the joints between the segments of each ringoffset from the joints between the segments of all the other rings,subjecting the stack of rings thus formed to pressure and heat to moldsaid rings into a permanent rim, cutting out a plurality of circular,flat blanks of wood, placing a plurality of said blanks upon each otherwith urea resin therebetween, subjecting said blanks to pressure andheat and simultaneously ofisetting the central portion of said blanks toform a permanent molded side plate, forming an axle core of wood,assembling said core and rim in spaced relation between a pair of sideplates and with urea resin between said side plates and the contactingsurfaces of said rim and core, and subjecting the assembly thus formedto heat and pressure to set said urea resin and thereby form apermanently bonded Wheel.

4'. That method of constructing a laminated wood wheel which comprisescutting out a plurality of equal arcuate wooden segments, arranging saidsegments to form a plurality of rings securing together the segmentsforming each ring, superimposing the several rings with urea resintherebetween, subjecting the stack of rings thus formed to pressure andheat to mold said rings into a permanent rim, cutting out a plurality ofcircular, flat blanks of wood, placing a plurality iii of said blanksupon each other with urea resin therebetween, subjecting said blanks topressure and heat to form a permanent molded side plate, forming an axlecore of wood, assembling said core and rim in spaced relation between apair of said side plates and with urea resin between said side platesand the contacting surfaces of said rim and core, subjecting theassembly thus formed to heat and pressure to set said urea resin andthereby form a permanently bonded wheel, forming a bearing in said sideplates and core, and inserting reinforcing rivets through said platesand rim.

5. That method of constructing a laminated wood wheel which comprisescutting out a plurality of equal arcuate wooden segments, ar rangingsaid segments to form a plurality of rings securing together thesegments forming each ring, superimposing the several rings with urearesin therebetween and with the joints between the segments of each ringoffset from the joints between the segments of all the other rings,subjecting the stack of rings thus formed to pressure and heat to moldsaid rings into a permanent rim, cutting out a plurality of circular,fiat blanks of wood, placing a plurality of said blanks upon each otherwith urea resin therebetween, subjecting said blanks to pressure andheat and simultaneously offsetting the central portion of said blanks toform a permanent molded side plate, assembling said rim between a pairof said side plates and with urea resin between said side plates and thecontacting surfaces of said rim, and subjecting the assembly thus formedto heat and pressure to set said urea resin and thereby form apermanently bonded wheel.

DAVID M. POPE. THOMAS F. SPACKMAN.

